This application is based on Application No. HEI 9-195332 filed in Japan, the content of which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an image forming apparatus such as a digital copier, facsimile, printer, and combinations thereof, and specifically relates to an image forming apparatus connected to an external device such as another image forming apparatus, computer or the like via a communications network.
2. Description of the Related Art
In recent years image forming apparatuses have appeared which are capable of continuously and sequentially printing image data stored in installed memory having relatively large capacity. Such image forming apparatuses are advantageous in reducing the overall processing time and increasing operation efficiency of the apparatus because a plurality of jobs stored in memory can be consecutively processed.
Specifically, in the digital copier provided with an image reader disclosed in Japanese Laid-Open Patent Application NO. HEI 4-306059, an operator can start a reading operation regardless of an on-going printing operation so as to reduce the waiting time in front of the copier by independently controlling the printing operation for stored image data as well as the reading operation of a plurality of documents.
This type of image forming apparatus reduces the waiting time of an operator, and operators frequently leave the apparatus.
In conventional image forming apparatuses, a printing operation is temporarily stopped when the paper cassette being used becomes depleted, when a paper jam occurs in the transport path, and when other abnormalities occurs such as the fixing heater is shut off, inadequate charging and the like.
From the perspective of recent international environmental regulations, it has become standard to provide a function to turn OFF the power supply automatically when a predetermined time has elapsed after the apparatus has stopped.
As described above, in image forming apparatuses provided with memory, an image is held in memory while the apparatus is stopped when an abnormality occurs such as depletion of the paper in a cassette. At this time, the operator is frequently absent from the apparatus for the previously described reasons, and when the apparatus has remained in this state for a predetermined time, the automatic power cut off function is activated. Normally, conventional image forming apparatuses are not provided with backup power supplies to achieve a more compact form factor for the apparatus and reduce the cost of the power supply and the like, such that the stored image data are erased when the power supply is turned OFF, and, disadvantageously, the image must be input again performing an image reading operation when power is restored.
The power supply is also shut OFF for safety reasons when correcting abnormalities such as clearing a paper jam and the like when the apparatus has stopped due to an abnormality as previously described. In such instances, image data stored in memory are erased causing a similar disadvantage.
An object of the present invention is to eliminate the previously described disadvantages by providing an image forming apparatus capable of executing continuous printing operations automatically without special procedures when the stopped state of the apparatus is released.
One aspect of the present invention is to provide, in an image forming apparatus, a memory means for storing input image data, image forming means for forming an image on a recording medium based on said stored image data, communication means for transmitting and receiving image data to/from an external device, detection means for detecting trouble relating to said recording medium, and a control means to transmit said image data to said external device via said communications means when trouble is detected by said detection means and to receive transmitted image data via said communications means after said trouble has been cleared.
Another aspect of the present invention is to provide, in an image forming apparatus, a memory means for storing input image data, image forming means for forming an image on a recording medium based on said stored image data, communication means for transmitting and receiving image data to/from an external device, power source condition detection means for detecting the ON/OFF condition of the power source, detection means for detecting trouble relating to said recording medium, and a control means to transmit said image data to said external device via said communications means when trouble is detected by said detection means and to receive transmitted image data via said communications means when a change in the power source from an OFF condition to an ON condition is detected by said power source condition detection means.
A further aspect of the present invention is to provide, in an image forming apparatus, a memory means for storing input image data, image forming means for forming an image by operating a plurality of image forming elements, communication means for transmitting and receiving image data to/from an external device, detection means for detecting trouble relating to at least one among said plurality of image forming elements, and a control means to transmit said image data to said external device via said communications means when trouble is detected by said detection means and to receive transmitted image data via said communications means after said trouble has been cleared.
Another aspect of the present invention is to provide, in an image forming apparatus, a memory means for storing input image data, communication means for transmitting and receiving image data to/from an external device, power source condition detection means for detecting the ON/OFF condition of a power source, detection means for detecting trouble relating to said apparatus, and a control means to transmit said image data to said external device via said communications means when trouble is detected by said detection means and to receive transmitted image data via said communications means when a change in the power source from an OFF condition to an ON condition is detected by said power source condition detection means.
Embodiments of the aforesaid aspects include, in the transmission of said image data to an external device, determination of the presence/absence of a communications-enabled external device, and determination of whether or not the available memory storage capacity can receive the amount of transmitted image data. Unnecessary transmission and reception are therefore avoided.
Embodiments of the aforesaid aspects further include, transmission of image data when there has been a lack of operation a predetermined time after detection of trouble. The disadvantage of erasure of image data is therefore avoided even when the power source has been turned OFF due to a lack of operation for a predetermined time.